Flue gas scrubbing apparatus



March 15, 1966 H. PRICE FLUE GAS SGRUBBING APPARATUS Filed April 29, 1963 1P M v/ R M fi 2 4 Z 6 0 4 3 W M ,4 TTUR/VE Y5 United States Patent 3,239,999 FLUE GAS SCRlJllBlNG APPARATUS Henry Price, Denver, (3010., assignor of one third each to 2111A. .lones, Denver, and Charles Ullrielr, Wheatridge,

Filed Apr. 29, 1963, Ser. No. 276,242 8 Claims. (Cl. 55-223) This invention relates to an apparatus for scrubbing or cleaning exhaust gases in order to render them free of any of the undesirable elements found in most industrial flue or exhaust gases.

While various devices have been provided for cleaning flue or exhaust gases, none of them have proved completely satisfactory and with the modern day increase in industrial activity there is a compelling need for flue or exhaust gas scrubbers or cleaning devices that will remove substantially all of the undesirable matter found therein. It is to be noted that substantially all of the prior art devices cause the flue gases to flow through the treating zone by means of a suitable pump or fan located at or near the entrance when the exhaust gases enter the reating zone. However, it has been found that this is not a suflicient manner of bringing the gases into and through the treating zone. Accordingly, this invention contemplates a removal of this deficiency by bringing the flue or exhaust gases into the treating zone by means of a negative pressure created by a suitable pump or fan system located at, or near, the exit at which the gases leave the treating zone. This negative pressure system utilized in this invention has the effect of sucking the exhaust gases through the treating zone in contrast to forcing the exhaust gases through the treating area by utilizing a positive pressure in the manner as described in the prior art.

It is, therefore, an object of this invention to provide an apparatus for removing all of the undesirable elements found in flue gases.

Another object of the invention is to provide an apparatus for scrubbing exhaust gases in which the gases are brought through the apparatus by creating a negative pres sure therein.

It is yet another object of this invention to provide a flue gas scrubbing apparatus in which any portion of the flue gas can be recycled to the furnace or other burning zone and then brought again into the treating area where further removal of the undesirable elements, if any, may be effected.

It is a further object of the invention to provide a flue gas scrubbing apparatus which can be easily and economically cleaned.

Other objects and a fuller understanding of the invention may be had by referring to the following description and claims, taken in conjunction with the accompanying drawing, in which:

FIGURE 1 is a cross-sectional view of the invention and including a furnace from which the flue gases are obtained; and,

FIGURE 2 is a cross-sectional view of the scrubber section of the invention showing only the compartmental divisions therein and omitting other essentials.

With reference to the drawing, a furnace is shown having the burners 12 located near the bottom in the burning zone 14 so that the flue gases which result from combustion within the burning zone pass upwardly and through the conduit 16 into the closed and air-tight flue gas treating chamber 22. The treating chamber 22 contains the removable top plate 19 held in place by the bolts 21a, b, c, d and e. It should be noted that the air vent 18 is provided to allow any desired amount of air to enter and mix with the flue gas as it enters into the 3,2393% Patented Mar. 15, 1965 inlet conduit 16. A vertically moveable door 21) is lo cated in close proximity to the air vent in order to control the amount of air entering and mixing with the flue gas. The provision for mixing air with the flue or exhaust gas dilutes the impurities within the flue gas thereby rendering them more easily removed in the treating chamber.

The conduit 16 carries the flue gas into the flue gas treating chamber 22 and extends to a level below the surface 24 of the body of liquid 26, which submerges the lower portion of the treating unit, thereby forming the compartment indicated as A. Located inside the compartment A is a second conduit 28 which carries the flue gas from the compartment A in an upward manner and then laterally into the second compartment indicated as B. From compartment B, a third conduit 29 carries the gas similarly to compartment C and so on, forming as many compartments as is necessary to properly treat the flue gas within the treating unit. The number of treating compartments discussed above having been multiplied a suitable number of times, finally open into the exit conduit 30 through the opening 32. The exit conduit extends beyond the treating area and near its discharge point 34 is located a fan 36 which may be of the squirrel cage blower type that draws or sucks the air through the treating unit in a manner such that the flue gas moves at a desirable speed, contacts the treating solution in a desirable rnanner as hereinafter described and effects a more efhcient and successful extraction of undesirable elements within the flue gas. The incorporation of a fan at or near the exit of the treating unit is one of the novel features of this invention. The devices of the prior art utilize a fan or pump near the entrance to the treating unit creating a positive pressure, resulting in only partlal and inefflcient removal of the undesirable elements, whereas, the employment of a fan or pump near the exit of the treating unit creates a negative pressure whereby the flue gas is drawn or sucked through the treating unit resulting in the novel improvements set forth above.

A motor 38 is mounted above the fan 36 and by means of the shaft 40 drives the fan 36. The shaft 40 extends downward into the body of water 26, which. immerses the lower portion of the treating unit, and also drives the water pump 42 having the propeller 44 located near the bottom of the body of water. The pump is preferably of the centrifugal variety, however, it can be of any type suitable for this purpose as is obvious to those familiar with the art. The pump 42 forces the water up the pipe 4-6 which has the spray ring 4% mounted thereon surrounding pipe 16. The spray ring includes a plurality of spray openings 50 and 52, so that when the water leaves the pipe 46 through the spray openings, it is formed into a fine spray directly into the path of the flue gas as it comes into the treating chamber via the conduit 16 and also into the area surrounding conduit 16. The pipe 46 terminates into a horizontal spray pipe 53 near the upper portion of the treating area and will also spray the water into the path of the flue gas. The spray water from the spray rings and the spray pipe will fall downwardly and entrap or dissolve the products to be removed from the flue or exhaust gases. The water pumped from the lower portion of the treating chamber and utilized as a spray may contain chemicals incorporated or dissolved therein which react or absorb any susceptible ingredients in the flue gas. The chemicals employed can be any of those used in the art for similar purposes. The spray rings and the spray pipes can be extended into any of the treating compartments, as set forth above, depending upon the individual desires and requirements of the particular flue or exhaust gases under treatment. It is, however, a preferred embodiment of this invention to provide for the final treating compartment to be free of spray rings and spray pipes, thereby insuring that the flue gas is substantially moisture free as it enters the exit conduit for removal from the system.

It should be noted that the above described arrangement whereby a series of treating compartments into which the flue gas flows for more etficient extraction of the undesirable elements by the aqueous spray is also one of the novel aspects of this invention, and it is easily seen by those familiar with the art that as the number of treating compartments within the treating area increases, the degree of removal of the undesirable elements within the flue gas will also be greatly increased. The number of separate compartments that can be utilized in this invention is limited only by the type of flue gas to be treated and economical and space factors.

Adjacent and lateral to the fan 36 employed for sucking air through the treating chamber is an air-tight section 54 adapted to receive the treated flue or exhaust gas from the fan 36. The aperture 56 leads from section 54 into a pipe 58 which in turn leads and opens into the burning zone 14 located within the furnace 10. The applicant has discovered that if a portion of the treated flue gases are returned to the burning or combustion area and then recycled through the treating unit, as described above, a better removal of undesirable elements is achieved. Within the section 54 is a movably mounted vane 60 which controls the amount of treated flue gas entering the pipe 58. Extending from section 54 is the pipe 62 which terminates in the discharge point 34 so that any gases not entering pipe 58 for reburning are discharged from the apparatus through the pipe 62. i

It has been mentioned previously that the lower portion of the treating area is submerged in water or water having dissolved chemicals therein and that this treated water is utilized as a spray for treating the flue gas as it passes through the treating area. As can be easily seen the water or chemically treated water will become dirty and contaminated after a period of time. Accordingly, the opening 64 and protruding pipe 66 are provided in the lower portion of the treating unit for removing the contaminated water and also to provide an entrance into the lower portion of the treating area for cleaning purposes. Whenever the treating area is to 'be filled with water or chemically treated water, it is merely pumped into the treating unit using the opening 64 and the pipe 66 and the treating unit is filled to the desired level.

It is clear that in operating my invention the flue gas from the furnace It) is directed through the conduit 16 after being diluted with air from the vent 18 as desired and thence into the treating chamber 22. The gas is directed through the compartments indicated as A, B, and C of the treating chamber 22 by the conduits 28 and 29. Within the compartments the flue gas is subjected to a water spray or a chemically treated water spray 'Which removes the undesirable ingredients therefrom.

The water is pumped from the lower portion of the treating chamber to the spray rings 48 and to the horizontal spray pipes 53 by means of the pipe 46 and the pump 42. The pump 42 is actuated by the shaft 40 which is, in turn, driven by the motor 38. The treated flue gas leaves the treating chamber through the opening 32 into the exit conduit 39 where it is drawn into the fan 36 which is actuated by shaft 49 which is, in turn, driven by the motor 38. The fan 36 diverts the flue gas into the section 54 where it is either discharged into the pipe 62 or is diverted into pipe 58 by means of the vane 60 which carries the gas to the burning zone 14 within the furnace and then recycled back through the treating unit as described above.

Although I have described my invention with a certain degree of particularity, it is understood that the present disclosure has been made only by way of example and that numerous changes in the details of construction and the combination and arrangement of parts may be resorted to without departing from the spirit and scope of the invention as hereinafter claimed.

What is claimed is:

1. A flue gas scrubbing apparatus adapted to receive flue gas from a combustion mean comprising in combination a treating chambers having a gas inlet conduit with an opening therein to admit air and the lower portion of said chamber being adapted to be filled with an aqueous solution to a desired level; a series of communicating com partmnts within the treating chamber and arranged in series, the first of said compartments being in communication with the gas inlet conduit; means for spraying the interior of the said compartments using the aqueous solution filling the lower portion of the housing unit, a water pump positioned within said treating chamber and adapted to force said aqueous solution through said spray means; an exit conduit communicating at one end with the last of the compartments in the treating chamber; a suction pump communicating with the other end of the said exit conduit and employed for drawing the flue gas through the treating chamber; and, an exhaust pipe in communication with the suction pump and adapted to discharge the treated flue gas from the apparatus including means to divert a portion of the flue gas from the exhaust pipe to the combustion means for reburning the flue gas and to recycle the flue gas to the treating chamber.

2. A flue gas scrubbing apparatus adapted to receive a fiue gas from a combustion means comprising in combination a treating chamber having a gas inlet conduit with an opening therein to admit air and the lower portion being adapted to be filled with an aqueous solution to a desired level, a series of communicating compartments within the treating chamber and arranged in series one after the other, the first of said compartments being in communication with the gas inlet conduit and each of the compartments having a conduit extending therefrom in direct communication therewith above the normal water level and opening into the following compartment providing access from one compartment to the next, means for spraying the interior of the said compartments using the aqueous solution filling the lower portion of the treating chamber, a water pump positioned Within said treating chamber and adapted to force said aqueous solution through said spray means, an exit conduit communicating at one end with the last of the compartments in the treating chamber, a suction pump communicating with the other end of the said exit conduit and employed for drawing the flue gas through the treating chamber, and an exhaust pipe in communication with the suction pump and adapted to discharge the treated flue gas from the apparatus including means to divert a portion of the flue gas from the exhaust pipe to the combustion means for reburning the flue gas and recycle the flue gas to the treating chamber.

3. A flue gas scrubbing apparatus adapted to receive flue gas from a combustion means comprising in combination a treating chamber having a gas inlet conduit with an opening therein to admit air and the lower por tion being adapted to be filled with an aqueous solution to a desired level, a series of communicating compartments within the treating unit and arranged in series one after the other, the first of said compartments being in communication with the gas inlet conduit and each of the compartments having a conduit extending therefrom in direct communication therewith above the normal water level and opening into the following compartment providing access from one compartment to the next, means for spraying the interior of the said compartments using the aqueous solution filling the lower portion of the treating chamber, a water pump positioned within said treating chamber and adapted to force said aqueous solution through said spray means, an exit conduit communicating at one end with the last of the compartments in the treating chamber and the other end extending outside of the treating chamber, a suction pump being in air-tight communication with the other end of said exit conduit and employed for drawing the flue gas through the treating chamber and a pipe having one end in communication with the pump exhaust pipe and the other end opening into said combustion means, said pipe having a vane moveably mounted therein and being adapted to pass a predetermined amount of treated flue gas into the combustion means to reburn the flue gas and recycle the flue gas to the treating chamber.

4. A flue gas scrubbing apparatus adapted to receive flue gas from a combustion means comprising in combination a treating chamber with a gas inlet conduit including an opening therein to admit air to dilute the flue gas and the lower portion of the treating chamber being adapted to be filled with an aqueous solution to a desired level, said treating chamber having a water removing outlet extending from the lower portion for the removal of the solution contained therein and adapted to permit cleaning of the interior of the treating chamber, a series of communicating compartments within the treating chamber and arranged in series one after the other, the first of said compartments being in communication with the gas inlet conduit and each of the compartments having a conduit extending therefrom in direct communication therewith above the normal water level and opening into the following compartment providing access from one compartment to the next, means for spraying the interior of the said compartments using the aqueous solution filling the lower portion of the treating chamber, a water pump positioned within said treating chamber and adapted to force said aqueous solution through said spray means, an exit conduit communicating at one end with the last of the compartments in the treating chamber and the other end extending outside of the treating chamber, a suction pump being in air-tight communication with the other end of said exit conduit and employed for drawing the flue gas through the treating chamber and a pipe having one end in communication with the pump exhaust pipe and the other end opening into said combustion means, said pipe having a vane movably mounted therein and being adapted to pass a predetermined amount of treated flue gas into the combustion means to reburn the flue gas and recycle the flue gas to the treating chamber.

5. A flue gas scrubbing apparatus adapted to receive flue gas from a combustion means comprising in combination a treating chamber having a gas inlet conduit with an opening therein to admit air and the lower portion of said chamber being adapted to be filled with an aqueous solution to a desired level; a series of communicating compartments within the treating chamber and arranged in series, the first of said compartments being in communication with the gas inlet conduit; means for spraying the interior of the said compartments using the aqueous solution filling the lower portion of said treating chamber, said solution being water having chemicals dissolved therein adapted to remove undesirable ingredients of a flue gas passing therethrough; an exit conduit communicating at one end with the last of the compartments in the treating chamber, a suction pump communicating with the other end of the said exit conduit and employed for drawing the flue gas through the treating chamber, and an exhaust pipe in communication with the suction pump and adapted to discharge the treated flue gas from the apparatus including means to divert a portion of the flue gas from the exhaust pipe to the combustion means for reburning the flue gas and to recycle the flue gas to the treating chamber.

6. A flue gas scrubbing apparatus adapted to receive flue gas from a combustion means comprising in combination a treating chamber having a gas inlet conduit with an opening therein to admit air and the lower portion being adapted to be filled with an aqueous solution to a desired level, a series of communicating compartments within the treating chamber and arranged in series one after the other, the first of said compartments being in communication with the gas inlet conduit and each of the compartments having a conduit extending therefrom in direct communication therewith above the normal water level and opening into the following compartment providing access from one compartment to the next, means for spraying the interior of the said compartments using the aqueous solution filling the lower portion of the treating chamber, said aqueous solution being water having chemicals dissolved therein adapted to remove undesirable ingredients of a flue gas passing therethrough; an exit conduit communicating at one end with the last of the compartments in the treating chamber, a suction pump communicating with the other end of the said exit conduit and employed for drawing the flue gas through the treating chamber, and an exhaust pipe in communication with the suction pump and adapted to discharge the treated flue gas from the apparatus including means to divert a portion of the flue gas from the exhaust pipe to the combustion means for reburning the flue gas and recycle the flue gas to the treating chamber.

7. A flue gas scrubbing apparatus adapted to receive flue gas from a combustion means comprising in combination a treating chamber with a gas inlet conduit including an opening to admit air to dilute the flue gas and the lower portion of the treating chamber being adapted to be filled with an aqueous solution to a desired level, said treating chamber having a water removing outlet extending from the lower portion for the removal of the solution contained therein and adapted to permit cleaning of the interior of the treating chamber, a series of communicating compartments within the treating chamber and arranged in series one after the other, the first of said compartments being in communication with the gas inlet conduit and each of the compartments having a conduit extending therefrom in direct communication therewith above the normal water level and opening into the following compartment providing access from one compartment to the next, means for spraying the interior of the said compartments using the aqueous solution filling the lower portion of the treating chamber, said aqueous solution being water having chemicals dissolved therein adapted to remove undesirable ingredients of a flue gas passing therethrough; an exit conduit communicating at one end with the last of the compartments in the treating chamber and the other end extending outside of the treating chamber, said suction pump being in air-tight communication with the other end of said exit conduit and employed for drawing the flue gas through the treating chamber and said pipe having one end in communication with the pump exhaust pipe and the other end opening into said combustion means, said pipe having a vane movably mounted therein and being adapted to pass a predetermined amount of treated flue gas into the combustion means to reburn the flue gas and recycle the flue gas to the treating chamber.

8. A flue gas scrubbing apparatus adapted to receive flue gas from a combustion means comprising in combination a treating chamber with a gas inlet conduit including an opening to admit air to dilute the flue gas and the lower portion of the treating chamber being adapted to be filled with an aqueous solution to a desired level, said treating chamber having a water removing outlet extending from the lower portion for the removal of the solution contained therein and adapted to permit cleaning of the interior of the treating chamber, a series of communicating compartments within the treating chamber and arranged in series one after the other, the first of said compartments being in communication with the gas inlet conduit and each of the compartments having a conduit extending therefrom in direct communication therewith above the normal Water level and opening into the following compartment providing access from one compartment to the next, means for spraying the interior of the said compartments using the aqueous solution filling the lower portion of the treating chamber, an exit conduit communicating at one end with the last of the compartments in the treating chamber and the other end extending outside of the treating chamber, said last com- 7 8 partment being free of said means for spraying the i-n- References Cited by the Examiner terior thereof; a suction pump being in air-tight commu- UNITED STATES PATENTS nication with the other end of said exit conduit and employed for drawing the flue gas through the treating 934'205 9/1909 NIX 261' 116 chamber and a pipe having one end in communication 5 1010608 11/1911 Pavena with the pump exhaust pipe and the other end opening into said combustion means, said pipe havlng a vane 1,793,620 2/1931 Jacobus 261 21XR movably mounted therein and being adapted to pass a predetermined amount of treated flue gas into the com- 1843999 2/1932 Whlte' bustion means to reburn the flue gas and recycle the flue 10 2302543 8/1957 Clark 55 212 XR gas to the treating chamber. HARRY B. THORNTON, Primary Examiner. 

1. A FLUE GAS SCRUBBING APPARATUS TO RECEIVE FLUE GAS FROM A COMBUSTION MEAN COMPRISING IN COMBINATION A THREATING CHAMBERS HAVING A GAS INLET CONDUIT WITH AN OPENING THEREIN TO ADMIT AIR AND THE LOWER PORTION OF SAID CHAMBER BEING ADAPTED TO BE FILLED WITH AN AQUEOUS SOLUTION TO A DESIRED LEVEL; A SERIES OF COMMUNICATING COMPARTMENTS WITHIN THE TREATING CHAMBER AND ARRANGED IN SERIES, THE FIRST OF SAID COMPARTMENTS BEING IN COMMUNICATION WITH THE GAS INLET CONDUIT; MEANS FOR SPRAYING THE INTERIOR OF THE SAID COMPARTMENTS USING THE AQUEOUS SOLUTION FILING THE LOWER PORTION OF THE HOUSING UNIT, A WATER PUMP POSITIONED WITHIN SAID TREATING CHAMBER AND ADAPTED TO FORCE SAID AQUEOUS SOLUTION THROUGH SAID SPRAY MEANS; AN EXIT CONDUIT COMMUNICATING AT ONE END WITH THE LAST OF THE COMPARTMENTS IN THE TREATING CHAMBER; A SUCTION PUMP COMMUNICATING WITH THE OTHER END OF THE SAID EXIT CONDUIT AND EMPLOYED FOR DRAWING THE FLUE GAS THROUGH THE TREATING CHAMBER; AND, AN EXHAUST PIPE IN COMMUNICATION WITH THE SUCTION PUMP AND ADAPTED TO DISCHARGE THE TREATED FLUE GAS FROM THE APPARATUS INCLUDING MEANS TO DIVERT A PORTION OF THE FLUE GAS FROM THE EXHAUST PIPE TO THE COMBUSTION MEANS FOR REBURNING THE FLUE GAS AND TO RECYCLE THE FLUE GAS TO THE TREATING CHAMBER. 